1. Field of the Invention
The present invention relates to a waterproof structure of a push button which is provided on electronic devices.
2. Description of the Related Art
Electronic devices are provided with push buttons, and enables inputs of characters and numbers and various instruction inputs by pressing a switch with push buttons. For an electronic device like a portable electric device, such as a cellular phone or a portable radio, various waterproof structures are proposed for preventing entering of water from a clearance between the push button and a casing. For example, Unexamined Japanese Patent Application KOKAI Publication No. 2001-222927 discloses a waterproof structure of a switch device which mounts a flexible substrate provided with a tact switch on the outer surface of a casing, and covers the flexible substrate by a waterproof member provided with a button section. The waterproof member is fixed by a fixation member having an opening corresponding to the button section, and the button section which protrudes from the opening of the fixation member is covered by a press-to-talk type button over the fixation member. Further, the fixation member is fixed by a top cover.
In this manner, the conventional waterproof structure of the switch device employs a complex structure. According to the conventional waterproof structure, because the tact switch and the flexible substrate are mounted on the outer surface of the casing, it is necessary to lead a part of wirings of the flexible substrate into the casing, so that the efficiency of an assemble work is not good.